Los Angeles Personal Trainer Lalo Fuentes shows you the:
SIDE LEG EXTENSIONS

EXPLANATION
In this next move, engage your gluts and raise your knee before extending your leg out to the side. From a standing position, bring your arms close to your side and raise your fists up to your shoulders in a fighters stance, elbows down. Push your weight through one heel and extend the opposite leg to the side. Never kick into the air, just extend your leg to the side with control. Keep your abs tight at all times and exhale as soon as your leg is fully extended. Hold for a second to connect with your glut and side muscles. As you lower your leg, take a little step with it, shifting your weight to the opposite leg between extensions to release the stress in your leg. Muscles: Gluts, Abs and Obliques.

TROUBLE-SHOOTING
Target Muscles
You should feel this in your gluts, so if youre feeling this in your quads, make sure your toes are pointing forward, not to the ceiling, as you extend.
Hips
If you feel too much stress in your hip, make sure youre double stepping on every repetition.